Correction to: Earnings beta

Review of Accounting Studies - A Correction to this paper has been published: https://doi.org/10.1007/s11142-021-09585-w     

Correction to: Earnings announcement return extrapolation

Review of Accounting Studies - A Correction to this paper has been published: https://doi.org/10.1007/s11142-021-09605-9     

A Stability Approach to Mean‐Variance Optimization

I jointly treat two critical issues in the application of mean‐variance portfolios, that is, estimation risk and portfolio instability. I find that theory‐based portfolio strategies, which are known to outperform naive diversification () in the absence of transaction costs, heavily underperform it under transaction costs. This is because they are highly unstable over time. I propose a generic method to stabilize any given portfolio strategy while maintaining or improving its efficiency. My empirical analysis confirms that the new method leads to stable and efficient portfolios that offer equal or lower turnover than and larger Sharpe ratio, even under high transaction costs.     

Correction to: Voluntary disclosure when private information and disclosure costs are jointly determined

Review of Accounting Studies - A Correction to this paper has been published: https://doi.org/10.1007/s11142-021-09623-7     

Motivate Teenagers to Study

As the growth of people, the brain will be mature gradually, so the teenagers＇ immature actions can be attribute to some areas of their brain which hasn＇t developed completely.As an English teacher, understanding this stage of psychological and phvsiological characteristics of students and then using some teaching means and adopting corresponding measures for classroom teaching would inject more energy and obtain a better teaching effect.     

Learning lessons: how to practice nudging around the world

Abstract

The aim of this article is to cover three things: (1) to introduce the context behind why a report prepared by the Organisation for Economic Co-operation and Development (OECD) in 2017 would be of such importance to researchers in various academic disciplines and public policy, (2) to present the details of a simple classification system that was applied to all 111 case studies of behavioural interventions (better known as nudges) referred to in the OECD (2017a OECD. 2017a. Behavioural Insights and Public Policy Lessons from Around the World.1-408 pp. OeCD Publishing. https://read.oecd-ilibrary.org/governance/behavioural-insights-and-public-policy_9789264270480-en. doi:10.1787/9789264270480-en.[Crossref] , [Google Scholar]) report, and (3) to discuss what needs to be done to help advance practitioners’ pursuit of effective behavioural interventions. This article aims to highlight the importance of accurately cataloguing the types of behavioural interventions that have been trialled/implemented across the world. By adopting an agreed classification system, researchers and practitioners can benefit from knowing what can work, and where it can work, as well as what does not work, in order to be better armed when considering the use of behavioural interventions to solve social policy issues.     

From insurance risk to credit portfolio management: a new approach to pricing CDOs

We present a new approach for pricing collateralized debt obligations (CDOs) which takes into account the issue of the market incompleteness. In particular, we develop a suitable extension of the actuarial framework proposed by Bayraktar et al. [Valuation of mortality risk via the instantaneous Sharpe ratio: Applications to life annuities. J. Econ. Dyn. Control, 2009, 33, 676–691], Milevsky et al. [Financial valuation of mortality risk via the instantaneous Sharpe-ratio: Applications to pricing pure endowments. Working Paper, 2007. Available at: http://arxiv.org/abs/0705.1302], Young [Pricing life insurance under stochastic mortality via the instantaneous Sharpe ratio: Theorems and proofs. Technical Report, 2007. Available at: http://arxiv.org/abs/0705.1297] and Young [Pricing life insurance under stochastic mortality via the instantaneous Sharpe ratio. Insurance: Math. Econ., 2008, 42, 691–703], which is based on the so-called instantaneous Sharpe ratio. Such a procedure allows us to incorporate the attitude of investors towards risk in a direct and rational way and, in addition, is also suitable for dealing with the often illiquid CDO market. Numerical experiments are presented which reveal that the market incompleteness can have a strong effect on the pricing of CDOs, and allows us to explain the high bid-ask spreads that are frequently observed in the markets.     

Calculation of Death-Rates with Regard to Migrations

Abstract

As is known, the death-rates of a population are usually worked out by the aid of the formula where D_x denotes the number of deaths at the age x - x + 1 year and where M_x signifies the average population in the same age group or the total observed risktime (expressed in years).     

Optimal Mortgage Refinancing: A Closed‐Form Solution

We derive the first closed‐form optimal refinancing rule: refinance when the current mortgage interest rate falls below the original rate by at least In this formula W(.) is (the principal branch of) the Lambert W‐function, where ρ is the real discount rate, λ is the expected real rate of exogenous mortgage repayment, σ is the standard deviation of the mortgage rate, is the ratio of the tax‐adjusted refinancing cost and the remaining mortgage value, and τ is the marginal tax rate. This expression is derived by solving a tractable class of refinancing problems. Our quantitative results closely match those reported by researchers using numerical methods.     

Temperature and Growth: A Panel Analysis of the United States

We document that seasonal temperatures have significant and systematic effects on the U.S. economy, both at the aggregate level and across a wide cross section of economic sectors. This effect is particularly strong for the summer: a F increase in the average summer temperature is associated with a reduction in the annual growth rate of state‐level output of 0.15 to 0.25 percentage points. We combine our estimates with projected increases in seasonal temperatures and find that rising temperatures could reduce U.S. economic growth by up to one‐third over the next century.     

Significance of log-periodic precursors to financial crashes

We clarify the status of log-periodicity associated with speculative bubbles preceding financial crashes. In particular, we address Feigenbaum's criticism ([A article="1469-7688/1/3/306"] Feigenbaum J A 2001 Quantitative Finance 1 346-60 [/A]) and show how it can be refuted. Feigenbaum's main result is as follows: 'the hypothesis that the log-periodic component is present in the data cannot be rejected at the 95% confidence level when using all the data prior to the 1987 crash; however, it can be rejected by removing the last year of data' (e.g. by removing 15% of the data closest to the critical point). We stress that it is naive to analyse a critical point phenomenon, i.e., a power-law divergence, reliably by removing the most important part of the data closest to the critical point. We also present the history of log-periodicity in the present context explaining its essential features and why it may be important. We offer an extension of the rational expectation bubble model for general and arbitrary risk-aversion within the general stochastic discount factor theory. We suggest guidelines for the use of log-periodicity and explain how to develop and interpret statistical tests of log-periodicity. We discuss the issue of prediction based on our results and the evidence of outliers in the distribution of drawdowns. New statistical tests demonstrate that the 1% to 10% quantile of the largest events of the population of drawdowns of the NASDAQ composite index and of the Dow Jones Industrial Average index belong to a distribution significantly different from the rest of the population. This suggests that very large drawdowns may result from an amplification mechanism that may make them more predictable.     

Book review

Georgina Ferry (2003) A Computer Called LEO: Lyons Teashops and the World's First Office Computer, London: Fourth Estate, pp. xii + 221. £15.99 (hbk), ISBN 1841-15185-8.     

Infrastructure endowment,financial constraints and willingness to engage in PPPs: The case of Poland

Public-private partnership (PPP) is widely considered to be a solution to overcoming a public infrastructure gap while providing value for money. A growing body of empirical research papers suggests that value for money is not the only reason for a government setting up PPPs. This paper presents a detailed analysis of why local municipalities in Poland have chosen the PPP route to develop public infrastructure.

IMPACT

Government’s investment opportunities are often restricted by debt limits. That is why a PPP can be an attractive solution. Municipalities in Poland seem to opt for PPPs to keep their debt figures low. There is a risk that they are choosing the PPP route for the wrong reasons. Therefore we suggest that legislation is needed that requires greater financial transparency of PPP projects. This could help verify whether PPPs are being compiled according to EUROSTAT rules and to assess if PPP really is the best available option in terms of value for money.